Question

- 20 - {-4-[-8+(12-6-2)+2+3]}

Answer 1

-20-{-4-[-8+8+2+3]}
-20-{-4-5}
-20-{-9}
-20+9
-29

Answer 2

-20-{-4-[-8+(6-2)+2+3]}
-20-{-4-{-8-4+2+3}]
-20-{-4-[-4+2+3]}
-20-{-4-[-2+3]}
-20-{-4-[+1]}
-20-{-4-1}
-20-5
-25